Wiring a wall light

LAST UPDATED: 10th January 2023 by The Editorial Team

Light on a wall

Summary: Step by step guide and video showing wiring a wall light: Learn how to wire a wall light, prepare a new lighting point, fit a mounting box, connect the wall light, and connect a switch.

How to wire a wall light

*Non-notifiable project providing that installation complies with Electrical Regulations.

When choosing a wall light, take note of whether it has an integral switch or whether you will be required to install a separate switch run from a junction box. Make sure that the light fitting is double insulated or has an earth core to earth it. If you wish to install a wall light outside, see the project: Installing an exterior wall light.

The wiring for a wall light.

Preparing a new lighting point

  • Cut off the power supply to the relevant circuit from the consumer unit.
  • Trace the circuit cable route with a cable detector or by gaining access to the ceiling cavity to find a suitable point to connect the fused spur to.
  • Install the spur by following one of the methods outlined in Extending Lighting Circuits. If your wall light has its own switch, you can run the spur directly from the lighting circuit to the new lighting point. To install a new switch or connect the light to an existing wall switch, you will need to add a junction box to the circuit.
  • Prepare the cable route for the spur cable to the lighting point.
  • If you wish to install a separate switch, prepare the cable route to the position of the junction box and from there, to the new lighting point. To connect to an existing switch, carefully enlarge the existing cable chase and feed new cable into the conduit.
  • The light fitting must be fixed securely to masonry or to a wall-stud. To fix a light fitting between two wall studs, cut a batten to fit between the joists, and drill a hole in the centre of it. Feed the cable through the hole in the batten and fix the batten to the studs with nails hammered at angles.
  • If the light fitting does not have a heat resistant unit containing the terminals, you will need to fit a mounting box in the wall.

Fitting a mounting box

Protect strip connectors in a mounting box, an architrave box, or a round dry-lining box in a stud wall.

  • Hold the mounting box against the wall at about 1.8m (6ft) from floor-level and draw around it.
  • Place a masonry bit on your drill and set the drill to the depth required by the mounting box.
  • Drill holes around and inside the outline to make chopping out the hole easier.
  • If the surface is plasterboard, cut out the hole with a padsaw blade.
  • Cut insulation away from around the light fitting.
  • If the wall is masonry, cut out the hole with a hammer and chisel or brick bolster.
  • Vacuum the hole and surrounding area.
  • Press out the plastic tab in the back of the mounting box to make a hole for the cable.
  • Insert an eyelet or grommet into the hole to prevent damage to the cables.
  • Feed the spur cable, and, if you are installing a switch, also the switch cable though the hole in the back of the mounting box and fit the box in the hole.
  • If you are fitting a Clip-in or dry-lining mounting box, the box should clip in to place as you slide it into the hole. If this does not happen, push the lugs inside the box outwards.
  • If you are fitting a mounting box to a masonry wall, mark the screw holes, then drill and plug the holes to screw the mounting box to the wall.
  • If you have a metal mounting box, ensure it is earthed by connecting a flying earth between the earth terminal on the face-plate and the earth terminal at the back of the mounting box.
  • Mark and drill the screw holes for the light fitting, inserting a wall plug or cavity plug if required.
  • Align the wall light so that the screw holes match up with the holes in the mounting box. If they do not align, mark, drill and plug the screw holes in the wall.
If using a metal mounting box, connect a flying earth core.
Connect the flex tails from the wall light so that live, neutral and earth cores are opposite each other.

Connecting the wall light

  • Prepare the spur cable and cores for connection.
  • Connect the cores to the terminals on one side of a connector block: connect the earth core to the central terminal and the live (brown) and neutral (blue) cores to terminals on either side.
  • Connect the flex tails from the wall light to the terminals opposite so that live cores are opposite each other, neutral cores are opposite each other etc. If the fitting is double insulated there will be no earth flex tail on the light fitting.
  • Connect the switch cable if necessary, and screw the light fitting over the mounting box.










Connecting a switch

  • Feed the switch cable through the hole in the back of the switch mounting box and screw the mounting box to the wall. To install a flush-mounted mounting box, follow the instructions for fixing a mounting box.
  • Prepare both ends of the switch cable and the cores, insulating bare earths.
  • Place a piece of brown insulation tape around the blue core to label it as live.
  • At a four-terminal junction box connect the live (brown) core from the flex or lighting fixture and the brown-tagged blue core (tagged live) from the switch cable to one terminal; connect all the remaining live red cores (from the spur cable and switch cable) to one terminal; the neutral black cores (from the spur cable and flex) to another terminal; and the earths to the last spare terminal.
  • If you are installing a new switch for the light fitting, at the switch, connect the cores to the face-plate terminals: live core to the top terminal marked TOP or COMMON, neutral core either of the bottom terminals and earth to the earth terminal in the switch mounting box.
  • If you wish the light fitting to be controlled by an existing switch, replace the existing switch face-plate with a two-gang switch. Connect the cores in the new switch cable to the first gang terminals and the original switch cable to the second gang in the same way as for a new switch.
  • Screw the switch face-plate to the mounting box.
  • Restore the power.

Tools needed

  • Insulated screwdriver
  • Trimming knife
  • Hammer
  • Drill
  • Cable connector tool

Materials needed

  • Extension socket OR sockets
  • Cleats
  • Wall plugs

Important note

The colour-coding system for electric cable changed in 2006, make sure you read Electric cable and flex to view the new information.

How to fit and wire a ceiling light video

The below video shows how to fit and wire a ceiling light, change ceiling rose pendant and explains lighting circuits

How to fit and wire a light switch video

The below video explains how to wire a one-way light switch

Author

The Editorial Team

The Editorial Team at lets-do-diy.com are a team of experts led by Mark Wilson. We have been creating DIY projects, articles, costs guides and product reviews since 2008. For more info see our about page.